class Solution {
    public String largestNumber(int[] nums) {
        int n = nums.length;
        // 轉(zhuǎn)換成包裝類型，以便傳入 Comparator 對象（此處為 lambda 表達(dá)式）
        Integer[] numsArr = new Integer[n];
        for (int i = 0; i < n; i++) {
            numsArr[i] = nums[i];
        }
        Arrays.sort(numsArr, (x, y) -> {
            long sx = 10, sy = 10;
            while (sx <= x) {
                sx *= 10;
            }
            while (sy <= y) {
                sy *= 10;
            }
            return (int) (-sy * x - y + sx * y + x);
        });
        if (numsArr[0] == 0) {
            return "0";
        }
        StringBuilder ret = new StringBuilder();
        for (int num : numsArr) {
            ret.append(num);
        }
        return ret.toString();
    }
}

func largestNumber(nums []int) string {
    sort.Slice(nums, func(i, j int) bool {
        x, y := nums[i], nums[j]
        sx, sy := 10, 10
        for sx <= x {
            sx *= 10
        }
        for sy <= y {
            sy *= 10
        }
        return sy*x+y > sx*y+x
    })
    if nums[0] == 0 {
        return "0"
    }
    ans := []byte{}
    for _, x := range nums {
        ans = append(ans, strconv.Itoa(x)...)
    }
    return string(ans)
}